Cases of extreme weather events hit 5-year high in India this Sept-Oct: IMD

Late withdrawal of monsoon among reasons for phenomenon; many scientists feel events such as floods and cloudbursts, among others are growing due to adverse impact of climate change

As the world debates the impact of climate change on various facets of life in Glasgow, India has, in September and October this year, recorded the highest number of cases of extreme weather events during the last five years due to the late withdrawal of the southwest monsoon and higher-than-normal low-pressure systems.

Though sometimes not directly attributed to climate change, several scientists, including those in the state-run India Meteorological Department (IMD), feel that incidents of extreme weather events such as floods, cloud bursts, and heavy concentrated rainfall in a short span, are growing due to the adverse impact of climate change.

Meanwhile, the IMD said the country recorded 125 extreme weather events in September-October.

Of these 89 extremely heavy rainfall events were recorded this September against 61 in the same month last year, 59 in 2019; 44 in 2018 and 29 in 2017.

In October, India recorded 36 such events compared to 10 in the corresponding period of 2020; 16 in 2019; 17 in 2018 and 12 in 2017, the IMD data showed.

The meteorological department said the causes of disastrous weather episodes included the late withdrawal of the monsoon, a higher-than-normal number of low-pressure systems during the period and the interaction of active western disturbances with low-pressure systems in October.

Nine low-pressure systems, including two cyclones, one deep depression and six lows, affected the country during the period.

Unprecedented extremely heavy rain in Uttarakhand on October 18-19 claimed 79 lives. The Himalayan state had 203.2 mm of rainfall against the normal of 35.3 mm in October.

Heavy to extremely heavy rain during October 17-19 due to interaction of a low-pressure area and an intense western disturbance caused flash floods and landslides in Uttarakhand and riverine flooding in west Uttar Pradesh.

Rainfall recorded below 15 mm is considered light, between 15 and 64.5 mm moderate, between 64.5 mm and 115.5 mm heavy, between 115.6 and 204.4 is very heavy. Anything above 204.4 mm is considered extremely heavy rainfall.

The southwest monsoon withdrew from the entire country on October 25 against the normal date of October 15, making it the seventh-most delayed retreat since 1975.

The country received "normal" rainfall during the four-month southwest monsoon season from June to September -- 87 cm against the Long Period Average (LPA) of 88 cm of 1961-2010 (99 percent of its LPA).

This is the third consecutive year that the country recorded rainfall in the normal or above-normal category. Rainfall was above normal in 2019 and 2020.